An international joint research group succeeded in developing a novel thermally activated delayed fluorescence (TADF) material which displays emission of light in colors from green to deep-red through Intersystem Crossing from the singlet to the triplet excitons, a world first. The results will contribute to R&D in white TADF light emitting devices for indoor and outdoor use through combination with TADF materials that emit light in shorter wavelengths (deep blue to yellow).